diff --git a/qtest.c b/qtest.c
index 5e0e9ec791..b03b68adb3 100644
--- a/qtest.c
+++ b/qtest.c
@@ -191,7 +191,7 @@ static void GCC_FMT_ATTR(2, 3) qtest_send(CharDriverState *chr,
     len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
     va_end(ap);
 
-    qemu_chr_fe_write(chr, (uint8_t *)buffer, len);
+    qemu_chr_fe_write_all(chr, (uint8_t *)buffer, len);
     if (qtest_log_fp && qtest_opened) {
         fprintf(qtest_log_fp, "%s", buffer);
     }